Five researchers from Graz University of Technology in Austria have demonstrated for the first time a cache on multi-core ARM processors used in Android devices. The team presented their findings at the recent Usenix Security Symposium.
A CPU cache attack is a side-channel information leakage attack that allows third parties to extract small portions of data from the CPU cache, which in turn can be used to infer details about the data being processed.
In the past, researchers have discovered many ways to carry out cache attacks.
As ARM is relatively new to the CPU market, researchers are only now beginning to explore the possibility of porting these older attacks to the new platform.
The researchers, led by Moritz Lipp, revealed in a technical paper presented at Usenix how they were able to use powerful cache attacks on ARM CPUs to compromise Android devices. They used techniques such as Prime+Probe, Flush+Reload, Evict+Reload, and Flush+Flush.
They stated that their attacks are so intrusive and persistent that they manage and monitor cache activity in the ARM TrustZone, a special area in the Android operating system that benefits from tough security measures because it processes sensitive cryptographic functions.
The researchers say their attack can also be carried out from normal userspace, without elevated privileges, and that it affects hundreds of millions of Android devices. The team presented their results to Google, which has already patched most of the issues.
